The Cheetah-cub robot weighs 1.1 kilograms (2.42 pounds). The robot’s metallic frame is 20.5 centimeters (eight inches) long and 16 centimeters high. It has four four legs. To make the robot’s legs, the researchers used springs to reproduce tendons and actuators, or small motors that convert energy into movement, to replace muscles. The robot has recorded a maximum speed of 1.42 meters (4.65 feet) per second, corresponding to 5.1 kilometers (3.1 miles) per hour.